Traditional drilling or rockbolting machines usually comprise a four-wheeled “carrier vehicle” part with rigid or articulated chassis, a part which bears at the front one or two drilling or rockbolting arms, the basic orientation of which is parallel to the direction of displacement of the machine. By way of examples, reference is here made to European patent application EP 0 890 704 A in the name of the Applicant, relating to a machine with articulated chassis, and to U.S. Pat. No. 3,917,005, which describes a rigid-chassis vehicle. Tracked carrier vehicles are also known in this field—see, for example, patent GB 1583574.
These existing machines are usually relatively space-consuming, especially in height, which prevents their use in mine galleries of low height. Moreover, the arrangement of their drilling or rockbolting arms generally only allows these machines to be used with their longitudinal displacement axis perpendicular to the working face.
Another problem encountered in the use of such drilling or rockbolting machines is the unevenness of the ground in the mine galleries over which the carrier vehicle has to move and has also to be immobilized for drilling or rockbolting operations. The ground in a mine gallery usually has substantial changes in level, from one point to another, and supports or “props” provided on these carrier vehicles, in addition to their wheels, are usually used to stabilize them in an arrested working position—see, for example, the aforesaid U.S. Pat. No. 3,917,005, or U.S. Pat. No. 3,851,481, or, indeed, German document DE 2855486 A.
The present invention sets out to eliminate these drawbacks or usage limitations of current machines by providing a particularly compact carrier vehicle, designed for use in low-height galleries and allowing a different and advantageous working method, whilst adapting to unevennesses in the ground.